• Korean Journal of Radiology
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• v.24 no.8
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• pp.807-820
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• 2023

Objective: To assess whether computed tomography (CT) conversion across different scan parameters and manufacturers using a routable generative adversarial network (RouteGAN) can improve the accuracy and variability in quantifying interstitial lung disease (ILD) using a deep learning-based automated software. Materials and Methods: This study included patients with ILD who underwent thin-section CT. Unmatched CT images obtained using scanners from four manufacturers (vendors A-D), standard- or low-radiation doses, and sharp or medium kernels were classified into groups 1-7 according to acquisition conditions. CT images in groups 2-7 were converted into the target CT style (Group 1: vendor A, standard dose, and sharp kernel) using a RouteGAN. ILD was quantified on original and converted CT images using a deep learning-based software (Aview, Coreline Soft). The accuracy of quantification was analyzed using the dice similarity coefficient (DSC) and pixel-wise overlap accuracy metrics against manual quantification by a radiologist. Five radiologists evaluated quantification accuracy using a 10-point visual scoring system. Results: Three hundred and fifty CT slices from 150 patients (mean age: 67.6 ± 10.7 years; 56 females) were included. The overlap accuracies for quantifying total abnormalities in groups 2-7 improved after CT conversion (original vs. converted: 0.63 vs. 0.68 for DSC, 0.66 vs. 0.70 for pixel-wise recall, and 0.68 vs. 0.73 for pixel-wise precision; P < 0.002 for all). The DSCs of fibrosis score, honeycombing, and reticulation significantly increased after CT conversion (0.32 vs. 0.64, 0.19 vs. 0.47, and 0.23 vs. 0.54, P < 0.002 for all), whereas those of ground-glass opacity, consolidation, and emphysema did not change significantly or decreased slightly. The radiologists' scores were significantly higher (P < 0.001) and less variable on converted CT. Conclusion: CT conversion using a RouteGAN can improve the accuracy and variability of CT images obtained using different scan parameters and manufacturers in deep learning-based quantification of ILD.

• IMMUNE NETWORK
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• v.24 no.2
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• pp.7.1-7.19
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• 2024

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×10⁵ plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×10² PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×10² PFU-virus-infected lungs from 2 dpi, but not in 1×10⁵ PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×10⁵ PFU; however, 1×1² PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.130-144
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• 1999

Purpose : Long-term use of Cyclosporine(CsA) reduce renal blood flow by afferent arteriolar vasoconstriction and lead to chronic pathologic changes of CsA nephrotoxicity - 1) interstitial nephritis(IN); tubular atrophy (TA) and/or interstitial fibrosis(IF),2) arteriolopathy(AP). The Object of this study is to estimate the incidence of chronic pathologic CsA nephrotoxicity by duration of treatment and type of renal disease, relationship between histologic and clinical nephrotoxicity, and optimal duration of CsA therapy. Methods : 102 children with steroid resistant or dependent nephrotic syndrome confirmed by renal biopsy and treated with CsA from 1986 to 1997 were enrolled in this study(58 MCNS, 10 FSGS, 10 MGN, 15 $Henoch-Sch\"{o}nlein$ purpura nephritis with nephrotic syndrome (HSPN) and 9 IgA nephropathy with nephrotic syndrome(IgAN)). CsA was administered for 1yr, 1.5yr, 2yr in 24, 12, 22 MCNS patients and 2, 2, 6 FSGS patients respectively, 1yr, 2yr in MGN and 1yr in HSPN and IgAN. Sequential biopsies were done in all 102 patients after CsA treatment for evaluation of pathologic nephrotoxicity. Results : Complete remission rate was 92.2% (100% in MCNS and MGN, 80% in FSGS, 86.6% in HSPN and 55.5% in IgAN). Incidence of relapse during 6months after CsA treatment was significantly decreased compaed with relapsing spisodes during 6months before CsA treatment in MCNS(P<0.0001) and FSGS(P<0.0001). According to pathologic changes, 71 patients(69.6%) showed no pathological change, 24 patients(23.5%) showed IN and 7 patients(6.8%) showed AP. IN was 16.6%, 33.3%, 27.2% in 1, 1.5, 2 year of CsA treatment group in MCNS. AP was 0%, 16.6%, 9% in 1, 1.5, 2 year of CsA treatment group in MCNS. 14 out of 58 MCNS(24.1%) showed IN and 4 out of 58 MCNS(6.8%) showed AP. Incidence of pathologic change was significantly lower in CsA therapy of <1yr than >1yr(P=0.03). There were no significant difference of incidence of pathologic change in original renal disease, age and sex. Conclusion : Duration of CsA treatment was significant risk factor for nephrotoxicity and optimal duration seemed to be 1 year. Pathologic change due to nephrotoxicity did not correlate with deterioration of renal function and only detectable by renal biopsy.

• Journal of Chest Surgery
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• v.31 no.2
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• pp.118-124
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• 1998

Minimally invasive coronary artery bypass grafting without using cardiopulmonary bypass (CPB) is a recently accepted modality of myocardial revascularization prcedures which is particularly suitable to the patients with lesions in the left anterior descending(LAD) and the right coronary arteries. Of the consecutive 35 patients of coronary artery bypass grafting performed at Sejong General Hospital from March to August 1996, six patients underwent minimally invasive coronary artery bypass grafting without CPB. All had stenotic lesions of the LAD more than 90%. Bypass grafting of the LAD was approached through midline sternotomy in one, through ministernotomy in two, and through limited left anterior thoracotomy in three patients, respectively. The internal mammary arteries were prepared without the use of thoracoscope. The mobilized mammary arteries were connected directly to the LAD in 5 patients, and the anastomosis required interposition of a segment of the radial artery in the remaining one. The diagonal branch was revascularized with the saphenous vein graft at the same time in one patient. No blood transfusion was necessary in 2 patients, and average blood required during surgery was 800ml in 4 patients. All patients were extubated from 4 to 14 hours(mean 9 hours) after operation. Early postoperative coronary angiography in 5 patients between 7 and 10 days after surgery has proved full patency of the grafts. With these limited clinical experiences, the clinical results demonstrated that minimally invasive coronary artery bypass grafting without CPB is an useful procedure especially in patients with isolated lesion in the proximal LAD.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.21-26
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• 2001

Purpose : This study was peformed to evaluate the cosmetic outcome of conservative treatment for early breast cancer and to analyze the factors influencing cosmetic outcome. Materials and Methods : From February 1992 through January 1997, 120 patients with early breast cancer were treated with conservative surgery and postoperative radiotherapy. The types of conservative surgery were quadrantectomy and axillary node dissection for 108 patients $(90\%)$ and lumpectomy or excisional biopsy for 10 patients $(8.3\%)$. Forty six patients $(38\%)$ received adjuvant chemotherapy (CMF or CAF). Cosmetic result evaluation was carried out between 16 and 74 months (median, 33 months) after surgery. The cosmetic results were classified into four categories, i.e., excellent, good, fair, and poor. The appearances of the patients' breasts were also analyzed for symmetry using the differences in distances from the sternal notch to right and left nipples. A logistic regression analysis was performed to identify independent variables influencing the cosmetic outcome. Results : Cosmetic score was excellent or good in $76\%$ (91/120), fair in $19\%$ (23/120) and poor in $5\%$ (6/120) of the patients. Univariate analysis showed that tumor size (T1 versus T2) (p=0.04), axillary node status (N0 versus N1) (p=0.0002), extent of surgery (quadrantectomy versus lumpectomy or excisional biopsy) (p=0.02), axillary node irradiation (p=0.0005) and chemotherapy (p=0.0001) affected cosmetic score. Multivariate analysis revealed that extent of surgery (p=0.04) and chemotherapy (p=0.0002) were significant factors. For breast symmetry, univariate analysis confirmed exactly the same factors as above. Multivariate analysis revealed that tumor size (p=0.003) and lymph node status (p=0.007) affected breast symmetry. Conclusion : Conservative surgery and postoperative radiotherapy resulted in excellent or good cosmetic outcome in a large portion of the patients. Better cosmetic results were achieved generally in the group of patients with smaller tumor size, without axillary node metastasis and treated with less extensive surgery without chemotherapy.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.530-542
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• 2000

Background : Nonspecific interstitial pneumonia (NSIP) has been reported recently to have shown much better response to medical treatment and better prognosis compared with idiopathic UIP. However, clinical characteristics of idiopathic NSIP discriminating it from UIP have not been clearly defined. Method : Among 120 patients with biopsy-proven diffuse interstitial lung diseases admitted to the Samsung Medical Center between July 1996 and March 2000, 18 patients with idiopathic NSIP were included in this study. Retrospective chart review and radiographic analysis were performed. Results : 1) At diagnosis, 17 patients were female and the average age was $55.2{\pm}8.4$ years (44~73 years). The average duration from development of respiratory symptom to surgical lung biopsy was $9.9{\pm}17.1$ months. Increase in bronchoalveolar lavage fluid lymphocytes ($23.0{\pm}13.1%$) was noted. On HRCT, ground glass and irregular linear opacity were observed, but honeycombing was absent in all patients. 2) Corticosteroids were initially given to 13 patients, but the medication was stopped in 3 patients due to severe side effects. Further medical therapy was not possible in 1 patient who experienced streroid-induced psychosis. Herpes zoster (n=3), tuberculosis (n=1), avascular necrosis of the hip (n=1), cataract (n=2) and diabetes mellitus (n=1) developed during prolonged corticosteroid administration. Of the 7 patients receiving oral cyclophosphamide therapy, hemorrhagic cystitis hindered one patient from continuing with the medication. 3) After medical treatment, 14 of 17 patients improved, and 3 patients remained stable (mean follow-up ; $24.1{\pm}11.2$ months). FVC increased by $20.2{\pm}11.2%$ of predicted value and the extent of ground glass opacity on HRCT decreased significantly ($15.7{\pm}14.7%$). 4) Of the 14 patients who had stopped medication, 5 showed recurrence of NSIP and 2 became aggravated during steroid tapering. All patients with recurrence showed deterioration within one year after completion of initial treatment. Conclusion : Since idiopathic NSIP has unique clinical profiles and shows good prognosis, diagnosis different from UIP, and aggressive medical treatment are needed.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.478-486
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• 2000

Background : In acute lung injury, alveolar macrophages play a pivotal role in the inflammatory process during the initiation phase and in the reconstruction and fibrosis process during the later phase. Recently, it has been proven that alveolar macrophages are constituted by morphologically, biochemically and immunologically heterogenous cell subpopulations. The possibility of alterations to these characteristics of the alveolar macrophage population during lung disease has been raised. To investigate such a possibility a hyperoxic rat lung model was made to check the distributional and morphological changes of rat alveolar macrophage subpopulation in acute hyperoxic lung injury. Method : Alveolar macrophage were lavaged from normal and hyperoxic lung injury rats and separated by discontinuous gradients of percoll. After cell counts of each density fraction were accessed, the morphomeric analysis of alveolar macrophages was performed on cytocentrifuged preparations by transmission electron micrograph. Result : 1. The total alveolar macrophage cell count significantly increased up to 24 hours after hyperoxic challenge (normal control group $171.6{\pm}24.1{\times}10^5$, 12 hour group $194.8{\pm}17.9{\times}10^5$, 24 hour group $207.6{\pm}27.1{\times}10^5$, p<0.05). oHoHH However the 48 hour group ($200.0{\pm}77.8{\times}10^5$) did not show a significant difference. 2. Alveolar septal thickness significantly increased up to 24 hours after hyperoxic challenge(normal control group $0.7{\pm}0.2{\mu}m$, 12 hour group $1.5{\pm}0.4{\mu}m$, 24 hour group $2.3{\pm}0.4{\mu}m$, p<0.05). However the 48 hour group did not show further change ($2.5{\pm}0.4{\mu}m$). Number of interstitial macrophage markedly increased at 24 hour group. 3. Hypodense fraction(fraction 1 and fraction 2) of alveolar macrophage showed a significant increase following hyperoxic challenge ($\beta=0.379$.$\beta=0.694$. p<0.05) ; however, fraction 3 was rather decreased following the hyperoxic challenge($\beta=0.815$. p<0.05), and fraction 4 showed an irregular pattern. 4. Electron microscopic observation of alveolar macrophage from each fraction revealed considerable morphologic heterogeneity. Cells of the most dense subfraction(fraction 4) were small, round, and typically highly ruffled with small membrane pseudopods. Cells of the least dense fraction (fraction 1) were large and showed irregular eccentric nucleus and high number of heterogenous inclusions. Conclusion : In conclusion, these results suggest that specific hypodense alveolar macrophage subpopulation may play a an important role in an acute hyperoxic lung injury model But further study, including biochemical and immunological function of these subpopulations, is needed.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.40-54
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• 2004

Purpose : Captopril (angiotension converting enzyme inhibitor) is known to have a radioproptective effect in the lungs, intestines and skin, but its effect in the heart is unclear. To investigate the radioprotectlve efiect and mechanism of captopril on the heart, the histopathological changes and immunohistochemical stains were compared with radiation alone, and radiation combined with captopril, in the rats. Materials and Methods : The histopathological changes and immunohistochemical stains ($TNF{\alpha}$, $TGF{\beta}1$, PDGF and FGF2) were examined in the radiation alone and the combined captopril and radiation groups, 2 and 8 weeks after irradiation. Each group consisted of 8 to 10 rats (Sprague-Dawley). Irradiation (12.5 Gy) was given to the left hemithorax in a single fraction. Captopril (50 mg/Kg/d) mixed with water, was given orally and continuously from the first week prior to, up to the 8th week of the experiment. Results : In the radiation alone group, the ventricle at 2 weeks after irradiation showed prominent edema (p=0.082) and fibrin deposit (p=0.018) compared to the control group. At 8 weeks, the edema was decreased and fibrosis increased compared to those at 2 weeks. The histopathological changes of the combined group were similar to those of the control group, due to the reduced radiation toxicity at 2 and 8 weeks. The endocardial fibrin deposit (p=0.047) in the atrium, and the interstitial fibrin deposit (p=0.019) and edema (p=0.042) of the ventricle were reduced significantly in the combined group compared to those in the radiation alone group at 2 weeks. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$, PDGF and FGF-2 in the radiation alone group were more increased than in the control group, especially in the pericardium and endocardium of the atrium at 2 weeks. At 8 weeks, the pericardial $TNF-{\alpha}$ and $TGF-{\beta}1$ in the radiation alone group continuously increased. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$ and PDGF were decreased in the combined group at 2 weeks. At 8 weeks, the expressions of $TNF-{\alpha}$ in the atrial and ventricular pericardia were markedly reduced (p=0.049, p=0.009). Conclusion : This study revealed that the early heart damage induced by radiation can be reduced by the addition of captopril in a rat model. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$ and PDGF were further decreased in the combined compared to the radiation alone group at both 2 and 8 weeks. From these results, it may be concluded that these cytokines probably play roles in the radioprotective mechanism of captopril from the radiation-induced heart toxicity, similarly to in other organs.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.17-24
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• 2004

Purpose: To evaluate the treatment outcomes after postmastectomy radiotherapy (PMRT) and chemotherapy in patients with breast cancer. Materials and Methods: The PMRT were retrospectively analyzed in 83 patients with stage II-III female breast cancer treated between 1989 and 1995. The median age was 46 years (range, 23-77): Seventy-seven patients had modified radical mastectomies, 5 radical mastectomies and 1 simple mastectomy. Three patients ($4\%$) had pathologically negative axillae, and the remaining 80 ($96\%$) had positive axillae. Eleven, 23, 44 and 5 patients had pathological stages IIA, IIB, IIIA, and IIIB, retrospectively. Eighty ($96\%$) patients were treated with hockey-stick fields. The median dose of PMRT was 50.4 ey, in 1.8 Gy fractions. Adjuvant systemic chemotherapy was given to 74 patients ($89\%$). CMF-based or doxorubicin-containing regimens were given to 54 patients ($55\%$). The median follow-up time was 82 months (range, 8-171) after the mastectomy. Results: The 5 and 10-year overall survival rates for all patients were 65 and $49\%$, respectively. The univariate and multivariate analyses of the factors affecting the overall survival revealed the stage to be the most significant prognostic factor (p=0.002), followed by the combination of chemotherapy. Thirteen patients $16\%$ developed a LRF, at an interval of 4-84 months after radiotherapy, with a median of 20 months. The only significant prognostic factor affecting LRF was the combination of chemotherapy, in both the univariate and multivariate analyses. With respect to the sequence of chemoradiation, the sequence had no saatistical significance (p=0.90). According to the time interval from mastectomy to the onset of radiotherapy, the LRFR of the patients group treated by RT within or after 6 month postmastectomy 6 months were 14 vs. $27\%$ respectively (p=0.24). One third of the pa41en1s (26/83) developed distant metastasis, in 2-92 months, after radiotherapy, with a median of 21 months. The most commonly involved site was bone in 13 cases. The pathological staging was the only significant prognostic factor in both the univariate and multivariate analyses that affected distant failure. Radiological finding of radiation pneumonitis on a simple chest x-ray was shown in $20\%$ (17/83), with a time interval ranging from 2 to 7 months post-radiotherapy, with a median of 3 months. The stable lung fibrosis settled in 11 patients ($65\%$). Conclusion: It was concluded through this analysis that the combination of PMRT with in chemotherapy resulted in better overall survival and local control than PMRT alone in patients needing PMRT.

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.932-943
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• 2000

Background : Nonspecific interstitial pneumonitis (NSIP) is most likely to be confused with usual interstitial pneumonitis (UIP). Unlike patients witþ UIP, the majority of patients with NSIP have a good prognosis, with most patients improving after treatment with corticosteroids. Therefore it is clinically important to differentiate NSIP from UIP. Up to now, the only means of differentiating these two diseases was by means of surgical lung biopsy. American Thoracic Society (ATS) proposed a clinical diagnostic criteria for UIP to provide assistance to clinicians in its diagnosis without surgical lung biopsy. This study is aimed to investigate whether there were clinical and radiological differences between NSIP and UIP, and the usefulness of ATS clinical diagnostic criteria for UIP in Korea. Methods : We studied 60 patients with UIP and NSIP confirmed by surgical lung biopsy. Clinical manifestations, pulmonary function test, arterial blood gas analysis, bronchoalveolar lavage (BAL), and high resolution computed tomography (HRCT) were evaluated and analyzed by Chi-square test or t-test. The clinical criteria for UIP proposed by ATS were applied to all patients with idiopathic interstitial pneumonia. Results : Forty-two patients with UIP and 18 with NSIP were pathologically identified. Among the 18 patients with NSIP (M : F=1 : 17), the mean age was 55.2$\pm$8.4 (44~73) yr. Among the 42 patients with UIP (M : F=33 : 9), the mean age was 59.5$\pm$7.1 (45~74) yr (p=0.046). Fever was more frequent in NSIP (39%) (p=0.034), but clubbing was frequently observed in UIP (33%) (p=0.023). BAL lymphocytosis was more frequent (23%) (p=0.0001) and CD4/CD8 ratio was lower in NSIP (p=0.045). On HRCT, UIP frequently showed honeycomb appearance (36 of 42 patients) though not in NSIP (p=0.0001). Six of 42 UIP patients (14.3%) met the ATS clinical criteria for IPF, and 3 of 16 NSIP patients (18.8%) met the diagnostic criteria. Conclusion : Being a relatively young female and having short duration of illness, fever, BAL lymphocytosis, low CD4/CD8 ratio with the absence of clubbing and honeycomb appearance in HRCT increase the likelihood of the illness being NSIP. The usefulness of ATS clinical diagnostic criteria for UIP may be low in Korea.